How old is your dog?
Is she having any trouble actually breathing?
Is she coughing?
Does she have any history of heart disease?
Did she swallow the food ok?
Does she appear to be distressed?
Thanks for the extra information.
It is certainly possible that something has been stuck in your dog's throat, or even up the nose. Being a spaniel, I imagine she likes to have a good sniff around and we occasionally see dogs with blades of grass or small seeds etc. up their nose or stuck at the back of the nasal cavity. Sometimes things do get lodged in either place, or they can have been removed by the dog coughing or sneezing but leave behind some residual inflammation and irritation which then causes continued snorting and coughing. This may settle with time if the problem has gone.
If your dog does not appear to be distressed and can rest comfortably then it would be worth seeing how she gets on over the next 24 hours or so. Provide lots of drinkingwater and I would feed little and often and soft food as you have. If the problem persists then you may have to go to the vets for them to have a look for something that shouldn't be there. She may need some anti-inflammatory treatment or a closer look at the back of the nose under anaesthetic.
I hope this helps,
I think the most important thing is to avoid her getting too excited or wound up so that she does not have to try to get air in too quickly - leave the walks for now and just let her out to the toilet, and try to avoid games and letting her get too out of breath.